Libya's rebels have advanced on the town of Brega, a strategically important oil port in eastern Libya that has been held by Qaddafi's forces since March. While reports conflict on whether they now have complete control of the town, the offensive is seen as one of their most ambitious to date.

CNN reports that the troops fielded thousands of landmines along the approaches to Brega as well as an intentional fire fed continuously by an oil pipeline, which slowed their advance. An expedition group entered the city ahead of the bulk of the troops and clashed with Qaddafi's forces. According to the CNN report, the troops are now about five miles from the town.

On Friday, Nato jets – soon to be bolstered by four extra Tornados from the UK – destroyed 14 military vehicles at Brega, compared with 17 destroyed there during the previous six days.

The rebel push on Brega is one of the most ambitious of the war, with newly trained units launching a three-pronged attack. While a central advance is struggling to clear minefields near Brega, other units have enveloped government forces from the north and south. The rebel forces say 10 fighters have died and 170 were wounded. Tripoli has released no casualty figures of its own.

"Supporters of such a decision are supporters of a policy of isolation, in this case the isolation of those forces that represent Tripoli," Russian Foreign Minister Sergei Lavrov said. Moscow is in contact with both Tripoli and the rebels, he said, and has recognized the NTC as a negotiating partner, but nothing further.

Russia has been wary of foreign intervention in Libya from the outset – it abstained, along with China, from voting on the United Nations resolution that authorized a foreign military intervention in Libya and afterward became a vocal critic of the mission.